Geographic Range

Borneo fruit bats (Aethalops aequalis) have been found in the northwestern mountains of Borneo, Sabah, Sarawak, Brunei and Kalimantan, with a range spanning the northwestern border of Malaysia and Indonesia. (Bates, et al., 2008)

Physical Description

Borneo fruit bats have grey-brown to dark reddish-brown fur that is thick and long on the dorsal surface, with paler coloring on their ventral side. Their calcar is not visible due to their dark wing membranes. Their interfemoral membrane is very small and reduced. Their muzzle is narrow and pointed. As one of the smallest Old World Fruit bats, Borneo fruit bats have forearm lengths between 42 and 46 mm. These bats do not have a tail or spots on their wings, which distinguishes them from spotted-winged fruit bats. Their most distinctive characteristic is their teeth; Borneo fruit bats may be distinguished from pygmy fruit bats by the equal length of their upper and lower incisors. A few of their characteristics are sexually dimorphic, specifically their skull length, the distance between their upper canine and first upper molar, their palate length and their dentary length. (Allen, 1938; Tingga and Abdullah, 2012)

Reproduction

There is little available information on the mating systems of Borneo fruit bats.

There is little information available about the reproductive behavior of Borneo fruit bats, although most old world fruit bats are seasonal breeders and females produce one offspring per year. Gestation for fruit bats typically lasts between 4 and 6 months. (O'Brien, 1993)

There is little information about the parental investment of Borneo fruit bats.

Lifespan/Longevity

There is little information available about the lifespan of Borneo fruit bats, but closely related fruit bats live long lives with low fecundity. (Welbergen, 2012)

Behavior

There is little information available about the behavior of Borneo fruit bats, though their close relatives roost upside down by their feet in large groups in trees during the day and are active at night, dawn and dusk. (Welbergen, 2012)

Food Habits

There is little specific information available about this species' diet. Like other Old World fruit bats, Borneo fruit bats feed on fruit juices. They bite into a fruit and mash it with their teeth, consuming the juice, and spitting out the fibrous parts. Their narrow muzzle allows them to reach into flowers and consume nectar. As a smaller fruit bat, they can hover in front of flowers or fruit while consuming them. (Welbergen, 2012)

Predation

There is little information about the predators of Borneo fruit bats, although humans are the major predator of species closely related to them. They may also be preyed on by large reptiles or birds of prey. (Welbergen, 2012)

Ecosystem Roles

There is little information on the ecosystem roles of Borneo fruit bats, although other fruit bats play a large role in pollination and seed dispersal. (Welbergen, 2012)

Conservation Status

Deforestation is the largest concern in the conservation of Borneo fruit bats, though it is a species of least concern according to the IUCN Redlist. There is concern that in the future more deforestation may occur due to road construction, montane vacation home construction and the expansion of agriculture in the mountains of Borneo. (Bates, et al., 2008)

Contributors

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

Disclaimer:
The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.